The production of superconducting strips for power applications requires the highest precision and the greatest possible material protection. Typically, 12 mm-wide stainless steel strips are processed with a nickel alloy and cut into several narrow partial strips, such as 3 or 4 mm-wide segments separated by gaps of only 0.5 mm. As the strips are also provided with sensitive PVD coatings, non-contact measurement is required to inspect their width and individual segments with high precision.
Real-time quality control for maximum process reliability
The compact, high-performance optoCONTROL 2700-40 LED micrometer from Micro-Epsilon enables non-contact measurement of the strip immediately after cutting, while the process is running. With a width of 12 mm, the continuous strip is captured within the optical micrometer’s measuring field. Using the ‘Multi-segment’ preset, both the total width and the width of the individual partial strips can be measured precisely. The narrow 0.5 mm gaps between the segments are also reliably detected and monitored. As the measurement data is transmitted to the control system in real time, the measured values can be used immediately for process control.
Maximum precision with minimum waste
The optical precision micrometers offer several decisive advantages for demanding cutting and coating processes. As non-contact measurement places no mechanical stress on the sensitive nickel and PVD layers, there is no risk of scratches or deformation.
At the same time, the optoCONTROL 2700-40 LED micrometers offer high precision, with a resolution of 10 nm and repeatability of ≤ 0.1 μm. This allows even extremely narrow partial strips to be reliably detected. With a measurement rate of 5 kHz, the sensors enable fast and seamless control of the running strips, so deviations are detected immediately and rejects are minimised. Flexible interfaces such as EtherCAT, PROFINET, Ethernet/IP and analogue signals also allow the system to be seamlessly integrated into existing cutting and production systems.
Planarity testing in hybrid bonding
In semiconductor manufacturing, the exact planarity of wafers is crucial to ensuring stable hybrid bonding processes. Capacitive distance sensors from Micro-Epsilon provide high-resolution, non-contact measurement of shape deviations on wafers and supply data for the adaptive levelling of bonding units.
Hybrid bonding is an advanced joining technology used in semiconductor production. It connects two wafers or chips, known as dies, directly through copper contact surfaces, eliminating the need for conventional solder balls. In modern die-to-wafer (D2W) and wafer-to-wafer (W2W) hybrid bonding, real-time planarity measurement is a key factor in process reliability.
Capacitive distance sensors play a central role by enabling non-contact measurement of wafer shape deviations caused by deflection, twisting or local warping. In this way, the sensors monitor wafer planarity and provide essential measurement data for the adaptive levelling of the bonding units.
Inline planarity control before bonding
Depending on the measurement task, sensor arrays scan the surfaces of the upper and lower wafers and record local elevations, depressions, inclinations or overall deflection. This measurement data is incorporated into an active position correction for the wafer stages.
If height differences are detected, the bonding unit can be aligned precisely on the Z-axis using piezo-actuators or precision axes, for example. For very small chips, segmented surfaces can also be used on the chuck, allowing individual areas to be levelled locally. This precise non-contact measurement helps create the uniform surfaces required for reliable bonding.
Thanks to their vacuum-compatible design, the compact sensors can be used in almost all areas of application.
For more information about sensors and non-contact measurement systems for semiconductor manufacturing, view the Micro-Epsilon semiconductor industry brochure, call the Micro-Epsilon sales department on +44 (0)151 355 6070 or email info@micro-epsilon.co.uk.
